/*
 *  Copyright 2019-2020 Zheng Jie
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package com.wdb.config;

import cn.hutool.core.lang.Assert;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.parser.ParserConfig;
import com.alibaba.fastjson.serializer.SerializerFeature;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.codec.digest.DigestUtils;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.autoconfigure.data.redis.RedisProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.cache.Cache;
import org.springframework.cache.annotation.CachingConfigurerSupport;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.cache.interceptor.CacheErrorHandler;
import org.springframework.cache.interceptor.KeyGenerator;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheConfiguration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisOperations;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.RedisSerializationContext;
import org.springframework.data.redis.serializer.RedisSerializer;
import reactor.util.annotation.Nullable;

import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.time.Duration;
import java.util.HashMap;
import java.util.Map;

/**
 * @author Zheng Jie
 * @date 2018-11-24
 */
@Slf4j
@Configuration
@EnableCaching
@ConditionalOnClass(RedisOperations.class)
@EnableConfigurationProperties(RedisProperties.class)
public class RedisConfig extends CachingConfigurerSupport {

  /** 设置 redis 数据默认过期时间，默认2小时 设置@cacheable 序列化方式 */
  @Bean
  public RedisCacheConfiguration redisCacheConfiguration() {
    FastJsonRedisSerializer<Object> fastJsonRedisSerializer =
        new FastJsonRedisSerializer<>(Object.class);
    RedisCacheConfiguration configuration = RedisCacheConfiguration.defaultCacheConfig();
    configuration =
        configuration
            .serializeValuesWith(
                RedisSerializationContext.SerializationPair.fromSerializer(fastJsonRedisSerializer))
            .entryTtl(Duration.ofHours(2));
    return configuration;
  }

  @SuppressWarnings("all")
  @Bean(name = "redisTemplate")
  @ConditionalOnMissingBean(name = "redisTemplate")
  public RedisTemplate<Object, Object> redisTemplate(
      RedisConnectionFactory redisConnectionFactory) {
    RedisTemplate<Object, Object> template = new RedisTemplate<>();
    // 序列化
    FastJsonRedisSerializer<Object> fastJsonRedisSerializer =
        new FastJsonRedisSerializer<>(Object.class);
    // value值的序列化采用fastJsonRedisSerializer
    template.setValueSerializer(fastJsonRedisSerializer);
    template.setHashValueSerializer(fastJsonRedisSerializer);
    // fastjson 升级到 1.2.83 后需要指定序列化白名单
    ParserConfig.getGlobalInstance().addAccept("com.wdb.domain");
    // 模块内的实体类
    ParserConfig.getGlobalInstance().addAccept("com.wdb.modules.mnt.domain");
    ParserConfig.getGlobalInstance().addAccept("com.wdb.modules.quartz.domain");
    ParserConfig.getGlobalInstance().addAccept("com.wdb.modules.system.domain");
    // 模块内的 Dto
    ParserConfig.getGlobalInstance().addAccept("com.wdb.modules.security.service.dto");
    // key的序列化采用StringRedisSerializer
    template.setKeySerializer(new StringRedisSerializer());
    template.setHashKeySerializer(new StringRedisSerializer());
    template.setConnectionFactory(redisConnectionFactory);
    return template;
  }

  /** 自定义缓存key生成策略，默认将使用该策略 */
  @Bean
  @Override
  public KeyGenerator keyGenerator() {
    return (target, method, params) -> {
      Map<String, Object> container = new HashMap<>(8);
      Class<?> targetClassClass = target.getClass();
      // 类地址
      container.put("class", targetClassClass.toGenericString());
      // 方法名称
      container.put("methodName", method.getName());
      // 包名称
      container.put("package", targetClassClass.getPackage());
      // 参数列表
      for (int i = 0; i < params.length; i++) {
        container.put(String.valueOf(i), params[i]);
      }
      // 转为JSON字符串
      String jsonString = JSON.toJSONString(container);
      // 做SHA256 Hash计算，得到一个SHA256摘要作为Key
      return DigestUtils.sha256Hex(jsonString);
    };
  }

  @Bean
  @Override
  @SuppressWarnings("all")
  public CacheErrorHandler errorHandler() {
    // 异常处理，当Redis发生异常时，打印日志，但是程序正常走
    log.info("初始化 -> [{}]", "Redis CacheErrorHandler");
    return new CacheErrorHandler() {
      @Override
      public void handleCacheGetError(RuntimeException e, Cache cache, Object key) {
        log.error("Redis occur handleCacheGetError：key -> [{}]", key, e);
      }

      @Override
      public void handleCachePutError(RuntimeException e, Cache cache, Object key, Object value) {
        log.error("Redis occur handleCachePutError：key -> [{}]；value -> [{}]", key, value, e);
      }

      @Override
      public void handleCacheEvictError(RuntimeException e, Cache cache, Object key) {
        log.error("Redis occur handleCacheEvictError：key -> [{}]", key, e);
      }

      @Override
      public void handleCacheClearError(RuntimeException e, Cache cache) {
        log.error("Redis occur handleCacheClearError：", e);
      }
    };
  }
}

/**
 * Value 序列化
 *
 * @author /
 * @param <T>
 */
class FastJsonRedisSerializer<T> implements RedisSerializer<T> {

  private final Class<T> clazz;

  FastJsonRedisSerializer(Class<T> clazz) {
    super();
    this.clazz = clazz;
  }

  @Override
  public byte[] serialize(T t) {
    if (t == null) {
      return new byte[0];
    }
    return JSON.toJSONString(t, SerializerFeature.WriteClassName).getBytes(StandardCharsets.UTF_8);
  }

  @Override
  public T deserialize(byte[] bytes) {
    if (bytes == null || bytes.length == 0) {
      return null;
    }
    String str = new String(bytes, StandardCharsets.UTF_8);
    return JSON.parseObject(str, clazz);
  }
}

/**
 * 重写序列化器
 *
 * @author /
 */
class StringRedisSerializer implements RedisSerializer<Object> {

  private final Charset charset;

  StringRedisSerializer() {
    this(StandardCharsets.UTF_8);
  }

  private StringRedisSerializer(Charset charset) {
    Assert.notNull(charset, "Charset must not be null!");
    this.charset = charset;
  }

  @Override
  public String deserialize(byte[] bytes) {
    return (bytes == null ? null : new String(bytes, charset));
  }

  @Override
  public @Nullable byte[] serialize(Object object) {
    String string = JSON.toJSONString(object);

    if (org.apache.commons.lang3.StringUtils.isBlank(string)) {
      return null;
    }
    string = string.replace("\"", "");
    return string.getBytes(charset);
  }
}
